1. Field of the Art
The present invention relates to a communication control system for transmitting and receiving serial signals between a transmitter controller and a receiver controller.
2. Prior Art
Digital controllers for various types of apparatus used in monitoring, controlling or the like are becoming more common nowadays. In addition, most of such controllers incorporate microcomputers. However, there is a distinct tendency for such apparatus to misoperate because of overrun, erroneous operation or the like of the microcomputers incorporated into such controllers. In communication control systems and those using serial signals for remote control, abnormal operation caused by overrun of the microcomputer on the receiver controller necessitates turning off the power to recover normal operation. To eliminate such disadvantage, an exclusive reset signal line interconnecting a transmitter controller and a receiver controller has been conventionally used to transmit a reset signal from the transmitter controller to the receiver controller, said reset signal line being different from a serial signal line.
A main object of using serial signals is to reduce the number of signal lines between the controllers. However, the use of a dedicated signal line as described above is in conflict with the object of using serial signals.